Steganography and digital watermarking are powerful techniques for protecting intellectual property by embedding signatures and other information in audio, video and other digital media. Recognizing these signatures and verifying their integrity identifies intellectual property to prevent its misuse, detect its modification or generate royalties.
The study of steganography encompasses the practice of hidden or obscured messages in printed and visible works, and includes outright cryptography and other ciphers which render the media unintelligible. Unlike cryptography, however, steganographic techniques in general do not obfuscate the underlying media item, and therefore do not draw attention the way encryption does. Therefore, while steganographic implementations may inject either readily visible or more obscured artifacts in the underlying media item, they generally do not prohibit intelligible reception by the user, but rather continue to merely denote the source or origin of the media item.
Identifying foreign executable software, i.e., software not intended for execution on a specific platform such as self-modifying malicious code, malware and pirated software, is more of a problem for software than for digital media. While encryption, code signatures, checksums and hash codes are common in the protection of executables, they are not in themselves executable. While these techniques secure transport, storage and validate origin and ownership as an important element of the chain of trust, they are removed prior to execution and can't protect the executable during actual execution.